


Fight Like Kids

by esbee



Category: Free!
Genre: F/M, Omorashi, slight incest?
Language: English
Status: Completed
Published: 2014-07-09
Updated: 2014-07-09
Packaged: 2018-02-08 02:52:49
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,555
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1924005
Author URL: https://archiveofourown.org/users/esbee/pseuds/esbee
Summary: <blockquote class="userstuff">
              <p>Rin and Gou revert back to their younger ways as they fight over who gets to use the bathroom first. Things start off playful, but end up in a way neither of the Matsuoka siblings could have ever predicted.</p>
            </blockquote>





	Fight Like Kids

“Wait! Let me go!”

“No way!”

“But…ladies first!!!”

“You’re not a lady…you’re my sister!”

Gou pouted, attempting to slow down the running figure in front of her by grabbing onto his dress shirt tightly. Rin reacted with a grunt, losing his balance a bit. He tossed a dirty look at her from over his shoulder, and she stuck out her tongue in response with a juvenile humming noise.

A lot of things had happened between the two of them over the past few years. For a long time even after he had returned to Japan, Gou had feared things would never be the same. Eventually, through the help of his friends, he’d warmed back into someone who actually felt like her brother again. He wasn’t exactly the same, but Gou wasn’t complaining. She was just glad to finally see him looking genuinely happy again.

And every now and then, when the circumstances were _just_ right, Gou would get to see her brother acting just like he was a kid all over again. They’d both revert to their old tendencies, taunting and fighting with each other playfully until they ended up on the floor heaping with laughter. And those were the moments Gou loved the most.

This was one of the moments.

They’d both just been dropped off by Miss Amakata after going out with a large group of their friends to celebrate the ending of summer break. The drive had been particularly long, and upon getting in the house they both had immediately started a dash towards the bathroom. The problem was they only had one- and Gou was not about to back down. She had to pee so badly she could hardly stand it.

This wasn’t a new argument for the two of them. When they were young, they fought about using the bathroom first almost constantly. It drove their mother absolutely insane- Gou laughed to herself, the memories filling her head as she attempted to slink past her brother in their narrow hallway.

“Oh no you don’t!” Rin nearly growled, reaching ahead of her and spreading his arms across the hall so she couldn’t get by. “I’ll be quicker, let me go first.”

“That’s a lie and you know it!” Gou joked, ducking under his arm. “You always get caught up looking at yourself in the mirror and take forever.”

Rin smirked and ran past her again, mumbling a “yeah, yeah, whatever sis,” as he passed. Gou chased after him, barely making it in time to grab the handle of the door before he could. Rin pressed his body against it quickly, so that she couldn’t pull the door open.

“I got here first! You lost, fair and square, let me open it!” Gou whined playfully, giving her older brother a pout. She was a having a good time, but for what it was worth, she _really had to go._ Her thighs pressed together tightly and she used all her weight to pull against the door knob. Her bladder was dangerously full, and she could almost feel the liquid sloshing inside of her. It was a sharp, irritating sensation that sent chills up her spine. She pouted deeper.

Rin wasn’t letting up, however. He pressed into the door harder, and shook his head. “No way, I’m not letting you win this one, Gou.”

“Rin, seriously,” she whined, her face starting to redden. “I _really, really_ have to go.”

“Then let me go first, and you can go after.”

Gou’s need to pee suddenly surged quicker within her, passing over her body and forcing her to jump in place a bit. “Y-you don’t understand! You can go pee outside or something, just let me use the toilet!”

Things were getting too awkward too quickly. She clutched onto the door handle, trying desperately to distract herself from the weight on her bladder, but it wasn’t helping. If Rin didn’t give in, she was _really going to pee herself._ She didn’t even think she could bear to wait and let him go first. This was urgent, and her heart started to pound as Rin still refused to give up.

Gou was about to get angry, but she noticed that Rin had brought his legs together as well, and she could see his thigh muscles flexing desperately from underneath his jeans. Her eyes widened a bit, her body reacting in a strange way. She let out a slow breath, trying to regain control of herself so she didn’t lose it and pee right then and there. “Rin, I understand that you need to go too, and I promise that I’ll be quick but you’ve _got_ to let me go first, I’m really….I _really got to go.”_

By this point Rin was blushing too, and slightly jumping in place, his heels lifting up and down rapidly. Sharp teeth were biting into his lip- Gou blushed deeper watching him, and realized that it wasn’t helping her situation any at all.

“Brother, please!”

Rin turned away stubbornly, crossing his arms. Gou pulled harder, nearly whining. “Please!!!”

Suddenly, Rin grunted a “Fiiiiiine” and lifted himself away from the door, and it came flinging open. The force Gou had been exerting on the doorknob now flung her backward, and her brother instinctively reached out to try and catch her, sending them both towards the floor. She landed half with one leg sprawled across Rin’s, and her back slammed against the opposite wall.

The surprise of the fall had been too much, and Gou winced and covered her mouth as the pee started to gush out from her. She tried her best to tighten her muscles, but she couldn’t work against the flow. It streamed down her legs and onto Rin, who she couldn’t bear to look in the face. It was such a relief, and left her feeling unbearably warm and unnerved. She felt like all her senses were heightened in a terrible way- the smell, the hot, wet feeling of her clothing against her skin, the trembling of her legs as she released. Her fingers tightened around her mouth, tears forming in her eyes.

Beside her, Rin had landed with his back against the wall too. She could hear his breath hitching in surprise, and she wanted to hide away as fast as she could. But she couldn’t- all she could bring herself to do was sit there in silence, her face turned away in shame.

That was, until she heard a sigh behind her, and felt something warm start to pool around the foot that was awkwardly sprawled between Rin’s legs. Her mouth dropped a bit and she turned her head slowly to see Rin beside her, his expression hazy and flushed as he pissed himself as well. The pee was coming out of him for a long time- darkening his jeans and spreading across the hallway floor with a low, streaming noise. Finally it subsided, and Rin closed his eyes, tipping his head back and letting out a long breath.

After a while, they made eye contact and Gou didn’t know what to think. It was surreal and terrible- but at the same time, it sparked something dangerous inside her. Half of her wanted to shower and leave and never think about it ever again, but the other half felt exhilarated and was begging her to run into her room and get off with her vibrator as quickly as she could. She wondered how Rin must feel- having been peed on by his sister and then pissing on her himself…would he just feel humiliated? Or would he feel something else too?

Perhaps they’d both end up just going to their rooms and masturbating, getting breathy and hot from opposite ends of the house- Gou shook her head, willing the images of her brother naked and panting while his hand worked himself, still covered in his own pee, to orgasm.

She could think about that later, when they weren’t sitting there wet and in utter silence.

Gou had finally gotten the will to speak, when Rin beat her to the punch and spoke first. “If you’d just let me go first this wouldn’t have happened.” He looked down, attempting a smirk.

Gou was surprised that responding came as easily as it did. “No way! I tried to tell you how much I needed to go! It’s easier for boys- you could’ve gone in the sink if you really needed to, for goodness sake!”

Rin laughed, his nose wrinkling. “That’s gross!”

“Well so is this!” Gou bit back, and then blushed, ashamed to have mentioned it verbally. Rin’s face fell a bit, and his voice softened.

“I guess you have a point. I’ll clean it up. You go take a shower.”

Gou breathed slowly, feeling awkward all over again. “You sure?”

Rin smiled at her widely, his eyes flashing. “Yeah, sis. Then we can forget this ever happened.”

“Right.”

“Right.”

But neither of them were prepared to forget, and as Gou had imagined, they both ended up masturbating that night, shame in their bellies as they thought of each other squirming and trying to hold it in as they got themselves off. And Gou realized that she was dreading the end of summer break and Rin moving back into Samezuka even more, for the completely wrong reasons.

**Author's Note:**

> This is by far not the best thing I've written but I needed to get it out of my system :0


End file.
